Conventionally, each phase of a motor and a control circuit unit for inverter control have been provided separately, each of which are electrically connected using an intermediate harness. However, in recent years, in order to reduce manufacturing time and labor for connecting the intermediate harness, as well as to minimize space, the integration of the motor and the control circuit unit for inverter control has been long studied.
Considering that a high electrical current flows in such a multi-phased motors, Japanese Patent Laid-Open No. 2006-81373 discloses such a design having a bus bar with a large cross-sectional area connecting a terminal connected to each phase of the motor and a terminal on the control circuit unit. In order to achieve high reliability, a bolt has generally been used to connect the terminals to each other either directly or through the intermediate harness.
Also, there has been disclosed a technique in which a metallic clip is used to connect the terminals to each other (for example, refer to Japanese Patent No. 3666354 and Japanese Utility Model Laid-Open No. 01-127172).
The connection of terminals to each other is required to achieve high reliability. In Japanese Patent Laid-Open No. 2006-81373, the terminals are connected firmly to each other using a bolt. However, the number of bolts corresponding to the number of motor phases, generally, three phases. Therefore, to connect the terminals to each other, a large number of bolts must be tightened, which increases the amount time and labor in manufacturing.
On the other hand, Japanese Patent No. 3666354 and Japanese Utility Model Laid-Open No. 01-127172, disclose a method in which the crimping force (contact load) between the terminals is increased by a clip. In this design, to increase the crimping force of terminals, the elastic force of clip should be increased. However, the increase in elastic force of clip increases insertion resistance of the terminal at the time of connection, which poses a problem of difficulty in connecting the motor and the control circuit unit to each other. Further, also in the case of the clip, similar time and labor are required to mount the clips to the number of terminals corresponding to the number of motor phases.